1. Field of the Invention
The present invention relates to a positive typed photosensitive composition used in a semiconductor manufacturing process.
2. Description of the Related Art
In general, most photosensitive compositions used in a semiconductor manufacturing process may exhibit a positive type, because an exposed portion is dissolved in an alkali aqueous solution by ultraviolet exposure. The composition may include a resin dissolved in the alkali aqueous solution, a photosensitive compound that is insoluble in the alkali aqueous solution and is sensitive to ultraviolet light, and other additives.
As an example of the resin dissolved in the alkali aqueous solution, a polyamide derivative may be given. This resin may be transformed into polyamide and polybenzoxazole by heat, thereby exhibiting characteristics of a heat-resistant resin. In a conventional art, a composition not having photosensitivity may be used, however, in recent years, there arises a tendency to prefer a composition having photosensitivity for the purpose of process simplification.
A photosensitive composition manufactured by using a general polyamide derivative may exhibit a poor thermal stability to adversely affect pattern formation, or exhibit a significant volume reduction, while being subjected to a crosslinking process at a temperature of about 350° C., and thus a separate crosslink agent may need to be used. In this case, due to characteristics of a compound having crosslink characteristics, a resolution of the pattern may be reduced, and a degree of intermolecular crosslinking may be severe during the crosslinking process, and thereby ductility of inherent characteristics of a polyimide resin may be deteriorated. These additives may reduce sensitivity when forming the pattern, and thereby a process time may be lengthened.
In a recent semiconductor manufacturing process, the photosensitive composition may be coated on a wafer to be subjected to a patterning, and heated at a temperature of about 350° C. for one hour so as to perform a crosslinking on a film. When a crosslinking temperature is increased, an adverse influence may be exerted on a semiconductor device.
Accordingly, there is a demand for a composition having high reliability even at a relatively low temperature.